Negative surprise from Progressive Dynamics

[Jeffjeeptj]

I am in the process of installing Lithium batteries (Battleborn) in my TT. The Surveyor came with a WFCO 8955 converter fuse/circuit assembly and has 6 gage wire. Based on a variety of multiple RV forum comments about how good Progressive Dynamics (PD) units are (and implied why you are an idiot if you do not replace the WFCO power supply with a PD), I selected the PD4655LIV power supply, which is supposed tp be a slide in replacement. What a negative surprise!

This was a factory sealed box, with a large label that says PD4655LIV. The wires expected to connect the power supply to the fuse circuit board are 18” long and are 10 gauge. These 10 gauge wires are soldered to the printed circuit board (PCB). An inspection shows the PCB cannot accept larger wires. There is also the standard statement, if the customer modifies this, warranty is void.

A check on the Blue Sea circuit wizard shows 6 gage is the right size. Even the WFCO has 6 gauge wire.

I personally ran my IOTA DLS-55 bench power supply at its full 55 amps thru 3 feet of 10 gage wire one time as an experiment to see how it did with my AGM battery. Wires got up to the temperature of “very uncomfortable to touch”.

The PD unit is being returned. They will not be considered by me for any other purchase. Etrailer is being excellent, even though this is a refund.

[A32Deuce]

I went with a Go Power 4 stage converter for my AGM batterys. Plugged into the outlet behind the CB/fuse panel like the original to the and the 6 gauge wire fit their respective location. A little longer then the original but worked out fine since the internal fan is bigger. No wires get hot. The unit doesn't get hot. Hardest part was lifting the end of the bed to unplug the old and plug in the new.

[Cherokee39]

The current carrying capacity of the wire is a combination of things. Wire type and insulation have a lot to do with it. What was the insulation type and temperature rating of the #10 wire on the power supply?

[TitanMike]

Originally Posted by Papa Roo

The current carrying capacity of the wire is a combination of things. Wire type and insulation have a lot to do with it. What was the insulation type and temperature rating of the #10 wire on the power supply?

One of those "things" is length.

To the OP, #10 wire is more than adequate for a 3' run (from converter to circuit board round trip). In fact for that length of run you could even use #12 and still have less than a 2% voltage drop.

FWIW, wire's are rated for temps that are often "uncomfortable to touch".

Take a common wire type, THHN, and it's rated for up to 90 C. How hot is that? Add 10 degrees and it would boil water.

Another factor, the greatest current draw will be the charging of the batteries and a 55 amp PD Converter, will probably only charge at a 30-40 amp rate on average. Perhaps less if there is any great distance between batteries and Converter.

I changed the converter in my WFCO 8955 to a PD 9160 AL for my Lithium batteries. On the old converter the distance from Converter circuit board to distribution circuit board was only about 9-10" so that 18" pigtail could be cut way down, reducing the voltage drop and heat even more. A foot of #10 wire with 55 amp flowing generates about 3 watts of energy. This means that foot of wire will get about as hot as a 3 watt light bulb.

[Jeffjeeptj]

I did not record that info, take a picture, and I do not remember. When I used the Blue Sea circuit wizard, i checked two ways, most and least conservative. I did enter a circuit distance of 3 feet (sum of the two 18” long leads).
The LEAST conservative did yield a 10 gage solution. I have been over-Nuclearized due to my past work history. I was very surprised by the small wire size. Nope, PD has no way of knowing where their device will be installed.

The charger is in the rear corner of my TT, under the fridge, limited ventilation, and the batteries are on the tongue about 28 feet (one way). Least conservative calculation will not be used.

So, back it went.

[babock]

An easy solution of course would to take that to a power post and transition to higher gauge wire. That's what I did with my solar controller becuase I was running 4 gauge wire from the panels and I transtioned to what the controller needed to see which was 6.

https://smile.amazon.com/Blue-Sea-Sy...s%2C230&sr=8-1

When I put in my PD lithium converter, I got rid of the one in the power panel which was at the far end of the trailer and put in a new stand alone one right next to the batteries. That is actually your best option.

[KyDan]

Two thoughts...
All those happy PD customers can't be wrong. (Including me)
You'll very likely never pull 55 amps anyway.

[babock]

Originally Posted by KyDan

You'll very likely never pull 55 amps anyway.

Actually, 100% likely since he is going to lithium. My converter maxes out its 60A for the entire charge time until the batteries become full and then it pretty much drops to zero once the BMS kicks in. That's the beauty of lithium batteries.

[TitanMike]

Originally Posted by KyDan

Two thoughts...
All those happy PD customers can't be wrong. (Including me)
You'll very likely never pull 55 amps anyway.

One day, right after I installed my Victron monitor I turned on EVERYTHING that ran off 12 volts with the converter off. All the lights, fans, ran the water pump and even hit the switch to retract the slide.

Max current I could get flowing was 25 amp (my slide only draws just over 7 amp). I suppose I could max out the converter if I had just turned it on and battery charge current was at it's max and I decided to power up everything I could think of on the 12 volt system.

[babock]

Originally Posted by TitanMike

One day, right after I installed my Victron monitor I turned on EVERYTHING that ran off 12 volts with the converter off. All the lights, fans, ran the water pump and even hit the switch to retract the slide.

Max current I could get flowing was 25 amp (my slide only draws just over 7 amp). I suppose I could max out the converter if I had just turned it on and battery charge current was at it's max and I decided to power up everything I could think of on the 12 volt system.

Have you tried it when charging up your BattleBorns? If you aren't maxing out the converter, you have some serious voltage drop somewhere.

[TitanMike]

Originally Posted by babock

Have you tried it when charging up your BattleBorns? If you aren't maxing out the converter, you have some serious voltage drop somewhere.

#4 awg between Converter and Batteries. "Calculated" voltage drop is less than 5%. Haven't gotten around to doing any testing but my batteries are charging in short times so that hasn't reached the top of my "list" yet.

[babock]

Originally Posted by TitanMike

#4 awg between Converter and Batteries. "Calculated" voltage drop is less than 5%. Haven't gotten around to doing any testing but my batteries are charging in short times so that hasn't reached the top of my "list" yet.

All I do is look at my Victron monitor while they are charging...60A!!

[TitanMike]

Originally Posted by babock

All I do is look at my Victron monitor while they are charging...60A!!

With the converter near the batteries and large wire (2/0 ?) I'd expect that.

[babock]

Originally Posted by TitanMike

With the converter near the batteries and large wire (2/0 ?) I'd expect that.

You don't even need 2/0 wire. Just keep voltage drop down.

[Jeffjeeptj]

2/0 wire is good, far better than #10.

[cavie]

Originally Posted by babock

You don't even need 2/0 wire. Just keep voltage drop down.

Larger GA wire is how you keep voltage drop down. That's how it works.

[babock]

Originally Posted by cavie

Larger GA wire is how you keep voltage drop down. That's how it works.

Or keep the wire length short which is what I was saying. The whole point of having the converter near the batteries.

[babock]

The way I have my lithiums set up, I have 4/0 go from the batteries to bus bars. From the bus bars I have additional 4/0 go to my inverter. The whole reason to have 4/0 is for the inverter. The converter that is mounted nearby is connected to that bus bar through 4 gauge wire with the output of the converter going through a breaker first.

So basically, from the converter, it is mainly 4 with a very short length of 4/0 for its final path to the batteries. 4 is plenty to allow a full 60A to charge the batteries from the converter.

[DouglasReid]

Originally Posted by Jeffjeeptj

I did not record that info, take a picture, and I do not remember. When I used the Blue Sea circuit wizard, i checked two ways, most and least conservative. I did enter a circuit distance of 3 feet (sum of the two 18” long leads).
The LEAST conservative did yield a 10 gage solution. I have been over-Nuclearized due to my past work history. I was very surprised by the small wire size. Nope, PD has no way of knowing where their device will be installed.

The charger is in the rear corner of my TT, under the fridge, limited ventilation, and the batteries are on the tongue about 28 feet (one way). Least conservative calculation will not be used.

So, back it went.

So, the #10 pigtail, connected to the #6 wire that runs all the way up to the batteries with a split bolt connector, taped well would actually not be a problem................

I can understand the "pride of authorship of your decision but it seems that decision may have been hastily based on erroneous information.

I can honestly say Ive been corrected in this and other forums when my initial thoughts/opinions were incorrect.............Happens to us all

[TitanMike]

Originally Posted by DouglasReid

So, the #10 pigtail, connected to the #6 wire that runs all the way up to the batteries with a split bolt connector, taped well would actually not be a problem................

Here's a pic of the WFCO fuse block where the #10 leads are supposed to be connected.


Wire connecting the fuse block to battery is also connected to one of these terminals. (large lugs on RH side of Pic which are actually on left in Power Panel).

The terminals will accept up to a 1/0 wire (at least the ones on my WFCO 8955 panel will and that's where I've connected my #4 awg battery wire) so I'm at a loss as to why there is a perceived issue with SHORT #10 wires, probably measuring a finished length or less than 12" each (2' total) connecting the converter to the fuse block.

Using this online wire size calculator https://www.wirebarn.com/Wire-Calculator-_ep_41.html

2 feet of #10 wire @ 60 amp yields only a 1% voltage drop and if a less conservative 2% drop was acceptable the #10 wire could run up to over 4 feet and remain within that limit.

As I mentioned earlier, even allowing for the power loss as expressed by I ^2 R, around 3 watts (or less) would be lost which would take the form of heat.

The converter itself will radiate more heat than that which will be dissipated by the fan.

FWIW, the PD 9200 series Converters are UL listed so I doubt that they would get that label if they used too small a wire.

Just my observations.

Note: I chose to install a PD9200 series converter when I upgraded my WFCO 8955. By removing the old 8955 converter section, removing a couple of "ribs" in the converter compartment and opening up the vent holes at each end, I was able to mount the 9200"floor mount" converter in the same space. The 9200 has no wires other than the power input cord attached. 12v connections are made at lugs, two each neg and positive, that will accept much larger wire sizes.

Someday, if I get around to running a 120 Volt line to my battery compartment, I'll move the converter closer to the batteries although I'm getting very satisfactory performance as is.